| // Copyright (c) 2010 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_NON_THREAD_SAFE_H_ |
| #define BASE_NON_THREAD_SAFE_H_ |
| #pragma once |
| |
| #include "base/platform_thread.h" |
| #include "base/thread_checker.h" |
| |
| // A helper class used to help verify that methods of a class are |
| // called from the same thread. One can inherit from this class and use |
| // CalledOnValidThread() to verify. |
| // |
| // This is intended to be used with classes that appear to be thread safe, but |
| // aren't. For example, a service or a singleton like the preferences system. |
| // |
| // Example: |
| // class MyClass : public NonThreadSafe { |
| // public: |
| // void Foo() { |
| // DCHECK(CalledOnValidThread()); |
| // ... (do stuff) ... |
| // } |
| // } |
| // |
| // In Release mode, CalledOnValidThread will always return true. |
| // |
| #ifndef NDEBUG |
| class NonThreadSafe { |
| public: |
| ~NonThreadSafe(); |
| |
| bool CalledOnValidThread() const; |
| |
| protected: |
| // Changes the thread that is checked for in CalledOnValidThread. The next |
| // call to CalledOnValidThread will attach this class to a new thread. It is |
| // up to the NonThreadSafe derived class to decide to expose this or not. |
| // This may be useful when an object may be created on one thread and then |
| // used exclusively on another thread. |
| void DetachFromThread(); |
| |
| private: |
| ThreadChecker thread_checker_; |
| }; |
| #else |
| // Do nothing in release mode. |
| class NonThreadSafe { |
| public: |
| bool CalledOnValidThread() const { |
| return true; |
| } |
| |
| protected: |
| void DetachFromThread() {} |
| }; |
| #endif // NDEBUG |
| |
| #endif // BASE_NON_THREAD_SAFE_H_ |